Battery keeps dying on me!

gadawg31

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Hello everyone,

I was wondering if anyone could tell me how to check to see if there is a draw on my battery? I spoke with a mechanic a while back and he mentioned to me about removing one of my battery cables and taking a test light, but I have a bad memory and he no longer works at the repair shop. Any suggestions? I have replaced my solenoid and had my starter tested, but it seems like my battery just does not have enough power even though it is a factory replacement. Thanks. gadawg31
 

dcgrazier

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I would disconnect a battery terminal after the battery is fully charged and read the voltage across the terminals. Let the battery set for the time you usually do and then check the battery for voltage across the terminals again and see what the change in voltage is. This will tell you if the battery is holding a charge or not. You may have a weak cell and it is drawing the battery down. You can also use a test light by removing a battery terminal and connecting it from the terminal you removed and the battery terminal. Make sure all switches are in the OFF position. If it lights, you have something that is not completely disconnected. Instead of a test light, you can use a Volt Ohm Meter in the amperage mode and check for a current draw.
 

jhwentworth

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Hello everyone,

I was wondering if anyone could tell me how to check to see if there is a draw on my battery? I spoke with a mechanic a while back and he mentioned to me about removing one of my battery cables and taking a test light, but I have a bad memory and he no longer works at the repair shop. Any suggestions? I have replaced my solenoid and had my starter tested, but it seems like my battery just does not have enough power even though it is a factory replacement. Thanks. gadawg31

You really have to use a meter to troubleshoot electrical problems; anything less and and it's "swap 'til you drop". Swapping parts is an expensive way to fix things.

With a $15-$20 meter you can read the voltage level of the battery. A fully-charged battery should read between 12.4-13 volts. Is the mower alternator charging the battery? You should read 13.5+ volts across the battery terminals with the engine running.
Does the engine start if you use jumper cables?
 

gadawg31

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Thanks dcgrazier for the info, I couldn't remember for the life of me how he told me to check with a test light. I do have a pretty good volt meter that I will check as jhwentworth suggested.

jhwentworth; my mower appears to be charging. Both the volt meter and crazy stick(the little meter stick built into the mower) state it is charging and the volt meter reads about 14.3 when running. Also, yes it will start if I jump it with another 12v battery.

I replaced the battery today, so after the 24hr trickle charge I am going to try it out and see what happens.

Again, thanks from both of you for the info. THis has to save me some money. v/r gadawg
 

noma

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Hi gadawg31

I'm sure you have checked this ,but are your battery cables and all connections good and clean this could be what doing it to.
 

Ric

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If the battery isn't charging and I believe you said you had changed it out for a new battery then you need to have the Stator checked or replaced. It regulates the voltage that the battery receives, and if the Stator isn't working right your battery will never hold a charge. The Mower will run but only as long as the battery holds up and if you have an electric PTO that's where you'll notice the failure first. Do have a question though, what type of mower are we talking about??
 
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jhwentworth

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If the battery isn't charging and I believe you said you had changed it out for a new battery then you need to have the Stator checked or replaced. It regulates the voltage that the battery receives, and if the Stator isn't working right your battery will never hold a charge. The Mower will run but only as long as the battery holds up and if you have an electric PTO that's where you'll notice the failure first. Do have a question though, what type of mower are we talking about??

The OP posted that he was reading 14.3V at the battery when the motor was running, which would indicate the charging system is working (he didn't state the engine RPMs when testing). He hasn't posted since he swapped out the battery.

The stator generates AC power through a long coil of wire passing by magnets, and the wattage output varies with engine RPM (higher RPM= more power). The AC power is carried to a rectifier that converts AC to DC, then to a voltage regulator. Most times the rectifier and regulator are in one package. Many times the electric lights are powered by AC power directly without conversion to DC or any regulation. If you measure the AC as it enters the rectifier/regulator you should see 30V+ AC.
If you have 30V+ at the rectifier/regulator you should have 13.5+- VDC output, if not, replace the rectifier/regulator. If no 30+ VAC, then check the stator resistance end to end, and to ground. You should have an open circuit between the stator coil and ground, and a low resistance measured between the two wires from the stator. Low resistance would be close to 1-2 ohms; an open would indicate a broken stator wire; a high resistance might be a bad connection. The magnets that are used to excite the stator coil are prone to coming loose from their mounts, and when loose may trash the stator If the stator coil isn't shorted to ground or open end to end, yet there isn't any AC power, check the magnets.

Good information on B&S charging systems can be found at http://www4.briggsandstratton.com/miscpdfs/RNT/alternator_replacement.pdf . Note that B&S refers to the stator, rectifier, and regulator as an alternator.
 
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